Can you fairly compare Jacob deGrom to Tom Seaver? At this point or in this era of baseball? I'm not so sure you can for many reasons.
There's no doubt deGrom is likeable, well-respected and can do it all; strikeout batters, go deep in a game, field and hit. He's a class act who already has won two Cy Young Awards and has lead the league in strikeouts and ERA.
However, Seaver did it all as well and got hurt a lot less often. The Hall of Famer also known as "The Franchise" and "Tom Terrific" pitched a lot longer (20 years). deGrom's is in his 8th season. When Seaver pitched throwing 100 mph didn't happen as often. deGrom in 2021 has thrown harder and hit 100 mph more often than in years past and I believe that has to be factored into his injuries/missed starts this season.
In 2021 deGrom's 8th season was not even half completed and he was on his way of earning himself a 3rd Cy Young Award. Or you can say he was the favorite. His incredible 2021 season was going great. He had an amazing ERA of 1.08 and was 7-2. However, after beening on the IL multiple times he did not pitch again after the All-Star break.
Seaver won 3 Cy Young Awards and threw one no-hitter in his career with the Reds. deGrom is yet to throw a no-hitter. deGrom led MLB in ERA in 2018 when he finished 10-9 with a 1.70 ERA. Those stats earned him his 2nd Cy Young.
Seaver in his 20-year career with Mets, Reds, White Sox and Boston led the league in strikeouts five times. He finished his career with 3640 strikeouts which is 6th best in MLB history.
Seaver led the league in wins three times. He won 25 games in 1969 the year the Mets won the World Series. Seaver's lowest ERA in any season was 1.76. deGrom lowest was 1.70 to date. He may break that mark this season.
Seaver for the longest time held MLB record for consecutive strikeouts in game with 10 until this season when Aaron Nola of the Phillies matched that feat ironically against the Mets. deGrom this season came close to matching that record, but fell one strikeout short.
Seaver's career numbers are stellar: 311-205 with a lifetime ERA of 2.86. He also led the league in strikeouts five times and in ERA three times.
deGrom's career numbers are impressive; 77-53 with a 2.49 ERA and 1476 strikeouts. Obviously the game has changed since the Seaver days. If you do a 8-year comparison. Seaver threw more innings 2166 vs. 1261 and had nearly double the wins; 146 vs. 77.
deGrom has only thrown 200+ innings three times and Seaver in all of his first eight seasons, but obviously the game as changed with the use or should say overuse of relievers.
It wouldn't be fair to compare complete games, but it is fair to compare wins (to some extent), losses and ERA. deGrom is an excellent hitter. This season he was batting .364 and had 6 RBIs. Seaver was also a good hitter and athlete as well as a determined competitor.
What you can compare a bit more accurately is the years Seaver spent with the Mets and project deGrom's. Seaver was with Mets 13 years. He went 198-124 with 2.57 ERA and had 2641 strikeouts. No Mets pitcher has won more games than Seaver and he's 1st in Ks. deGrom projected over 13 years would be approximately 148-93 with a 2.41 ERA and 2845 Ks.
deGrom is likely to beat him in ERA and in strikeouts that's IF... he stay healthy. However, Seaver's 198 wins with the Mets in this baseball won't be beat by deGrom, not in this baseball era.
Hitting-wise I'd give the edge to deGrom the former shortstop. If deGrom wins a 3rd Cy Young he belongs in the same conversation as being the current day Tom Seaver.
However, let's see how much longer the 33-year current Mets ace pitches. Will he pitch into his 40's like Seaver did? Most likely not, unless he stays healthy. Will he win a World Series ring like Seaver did?
You would never see Seaver take himself out of a game as deGrom has done numerous times this season alone. Granted deGrom's reasoning was understandable and justified. It's understood he didn't want to risk further injury and wanted to be cautious for his team's and his career sake.
Again, the game has changed. There was no MRI back in the Seaver pitching days (1967-1986) and star starters like Seaver often went 8 or 9 innings each start unless they were getting bombed and that was a rarity when Seaver pitched. Back then hardly any managers employed a 100 pitch count.
Sadly Seaver passed away in 2020 at age 75. Mets renamed their stadium address at Citi Field in Queens to 41 Seaver Way. In 2022 a statue will be erected in his honor.
It's very possible deGrom may end up in the Hall of Fame. Let's hope if you're a Mets fan, he ends his career with the Mets and not with some other team like Tom Terrific did.